CVE-2026-2272 Overview
A critical integer overflow vulnerability has been identified in GIMP, the popular open-source image editing software. The flaw exists in the processing of ICO (Windows icon) image files, specifically within the ico_read_info and ico_read_icon functions. When processing specially crafted ICO files, a size calculation for image buffers can wrap around due to a 32-bit integer evaluation, allowing oversized image headers to bypass security checks. This can lead to buffer overflow and memory corruption, potentially resulting in application-level denial of service.
Critical Impact
A remote attacker can exploit this vulnerability by providing a malicious ICO file, causing GIMP to crash through memory corruption, resulting in denial of service.
Affected Products
- GIMP (GNU Image Manipulation Program) - versions with vulnerable ICO file handling
- Linux distributions packaging affected GIMP versions
- Windows and macOS builds of affected GIMP versions
Discovery Timeline
- 2026-03-26 - CVE-2026-2272 published to NVD
- 2026-03-26 - Last updated in NVD database
Technical Details for CVE-2026-2272
Vulnerability Analysis
This vulnerability is classified as CWE-190 (Integer Overflow or Wraparound). The issue stems from improper handling of size calculations when parsing ICO image files. The ico_read_info and ico_read_icon functions perform arithmetic operations on 32-bit integers to calculate buffer sizes for image data. When an attacker supplies a specially crafted ICO file with oversized image header values, these calculations can overflow, wrapping around to a smaller value than expected.
The integer overflow allows the allocation of an undersized buffer while the application subsequently attempts to copy more data than the buffer can hold. This mismatch between allocated buffer size and actual data written leads to a heap-based buffer overflow condition, corrupting adjacent memory regions.
Root Cause
The root cause lies in the lack of proper bounds checking before performing arithmetic operations on image dimension and size values within the ICO parsing code. The 32-bit integer used for size calculations is insufficient to safely handle the multiplication of large width, height, and color depth values that can be specified in a malicious ICO file header. Without validation to ensure the calculated size does not exceed the maximum value representable in a 32-bit integer, the arithmetic operation wraps around, producing an incorrect (smaller) result.
Attack Vector
The attack is network-based and requires user interaction. An attacker must convince a victim to open a maliciously crafted ICO file in GIMP. This could be accomplished through:
- Sending the malicious file via email as an attachment
- Hosting the file on a website for download
- Including the file in a compressed archive with other legitimate files
- Distributing through file-sharing platforms
When the victim opens the ICO file, GIMP's image parsing routines process the malformed header data, triggering the integer overflow during buffer size calculation. The subsequent buffer overflow corrupts heap memory, leading to application crash and denial of service.
The vulnerability manifests in the ICO file parsing routines within the ico_read_info and ico_read_icon functions. When these functions calculate the required buffer size for image data, they multiply image dimensions without checking for integer wraparound. For detailed technical analysis, see the GNOME GIMP Issue #15617 and Red Hat Bug Report #2438428.
Detection Methods for CVE-2026-2272
Indicators of Compromise
- GIMP application crashes when opening ICO files
- Unexpected GIMP process termination with segmentation fault errors
- Core dump files generated during ICO file processing
- Error logs indicating memory allocation failures or corruption in image processing
Detection Strategies
- Monitor for GIMP process crashes with signals indicating memory corruption (SIGSEGV, SIGABRT)
- Implement file type analysis to identify potentially malicious ICO files with anomalous header values
- Deploy endpoint detection rules to flag unusual memory access patterns during image processing
- Use application crash monitoring to correlate GIMP crashes with recently accessed ICO files
Monitoring Recommendations
- Enable application crash reporting and logging for GIMP processes
- Monitor file access patterns to identify suspicious ICO files from untrusted sources
- Implement network-level inspection for ICO files with malformed headers in email attachments or downloads
- Configure SIEM rules to alert on repeated GIMP crashes associated with the same user or file source
How to Mitigate CVE-2026-2272
Immediate Actions Required
- Update GIMP to the latest patched version when available from the vendor
- Avoid opening ICO files from untrusted or unknown sources
- Consider temporarily disabling ICO file type association with GIMP until patched
- Review and apply any security advisories from your Linux distribution or operating system vendor
Patch Information
Security updates addressing this vulnerability are being tracked through the GNOME GIMP project. For the latest patch status and remediation guidance, consult the following resources:
Monitor your Linux distribution's security update channels for patched GIMP packages.
Workarounds
- Configure file manager to not automatically open ICO files with GIMP
- Use alternative image viewers for ICO files until GIMP is patched
- Implement application sandboxing (e.g., Flatpak, Snap, or Firejail) to limit the impact of crashes
- Pre-validate ICO files using security tools before opening in GIMP
# Example: Use Firejail to sandbox GIMP and limit crash impact
firejail --private gimp malicious_file.ico
# Alternative: Check ICO file header for anomalies before opening
file suspicious.ico
hexdump -C suspicious.ico | head -20
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
